Subcutaneous phaeohyphomycosis of the finger caused by Exophiala spinifera

Abstract

A patient with severe rheumatoid arthritis treated with prednisone had a painless soft tissue nodule develop on the dorsal aspect of the ring finger. She denied any history of hand trauma, animal exposure, or systemic symptoms such as fever or malaise. Fungal cultures performed on an aseptically obtained aspirate of this lesion demonstrated dark, olive-black creamy colonies on Sabouraud's agar. Slide cultures made from mold colonies produced slender conidial forms with annellations and spine-like conidiophores, features characteristic of Exophiala spinifera. The lesion was surgically excised, and the patient was successfully treated with a course of oral itraconazole. This nodular lesion has not recurred at the time of this writing. Exophiala species are difficult to differentiate, and E. spinifera may be confused with Exophiala jeanselmei. A literature review will consider Exophiala species and clinical manifestations produced by these dematiaceous fungi.